Carbon Stock Differentials and Sequestration Potential under Different Cropping Systems in a Tropical Monsoon Region, South-West India.

The study estimates the soil organic carbon stock under various cropping systems to assess their sequestration potential in a tropical monsoon region, namely the Chulliyar-Ikshumathi sub-watershed of Bharathapuzha in Kerala, India. The cropping systems selected are the paddy, vegetables, coconut-arecanut groves, homestead farms, and mango plantations. The standard soil analyzing procedures to collect and analyze 129 soil samples from 43 locations were followed. The carbon stock (CS) of 0–10, 10–20, and 20–30 cm depth layers at each sampling location was estimated following the Walkley-Black method. The sequestration potential of soil under each cropping system is estimated to suggest an optimal cropping system for the region. The CS decreased with depth, irrespective of cropping systems. Among the cropping systems, the mango plantations, which practiced zero/no-tillage, have stability in the distribution of CS, while paddy fields showed higher variability in the CS. Even though mango plantations have more carbon sequestration potential (CSP), the coconut-arecanut grove is a better candidate for carbon sequestration (CSeq) in this region owing to its wider areal extent and acceptability. This analysis reveals the importance of assessing CS at the watershed level for sustainable land use planning to achieve better sequestration of atmospheric carbon. [ABSTRACT FROM AUTHOR]